Ratchet wrenches are known for rotating threaded fasteners, such as nuts, bolts, and screws, in one direction while the wrench handle is pivoted in a like direction. When the wrench is rotated in an opposite direction, the wrench's driving element should be disengaged, such that the fastener maintains a stationary position. In this manner, the fastener may be driven to complete insertion or removal without removing the wrench from the fastener.
Unfortunately, many conventional ratchet wrenches only partially achieve this intended operation in certain circumstances. After the wrench is pivoted in the desired direction, the ratchet drive is disengaged, but the wrench nevertheless exerts some frictional or mechanical force on the fastener, tending to rotate the fastener in an unintended reverse direction. Such force is normally resisted by the frictional engagement of the threads of the fastener with the threads of the work piece, but the fastener nevertheless turns when the threaded engagement is loose, as when the fastener is just starting to be tightened. The fastener, as a result, may oscillate back and forth with the forward and backward strokes of the wrench handle.
A conventional ratchet wrench may be manipulated to overcome an oscillating movement of a fastener when it occurs, but such manipulations are cumbersome and compromise the ability of the user to know the extent to which the fastener has been driven. Many wrenches must be removed repeatedly from the fastener, pivoted rearwardly, and then realigned with the fastener. This procedure becomes frustrating and more time consuming when realignment of the fastener and wrench is not quickly achieved.
It is accordingly an object of the present invention to provide a ratchet wrench that predictably drives a fastener when the wrench is rotated in one direction, and exerts negligible torque on the fastener when rotated in an opposite direction.
It is a further object of the present invention to provide a ratchet wrench that is operable in forward, reverse, and neutral positions without having to remove the wrench from the nut or bolt.
It is a still further object of the present invention to provide a ratchet wrench where a force that causes a pawl to achieve an engaging position is applied in the same direction as a force applied to the wrench handle to drive a fastener.
It is another object of the present invention to provide a ratchet wrench that is provided with a means for securing a pawl in at least three positions.
It is a yet another object of the present invention to provide a ratchet wrench having a pawl for changing among forward, reverse, and neutral positions that is operable entirely by one hand from the handle of the wrench, away from the area of the fastener.
Other objects of the invention will become apparent to those skilled in the art from a reading of the following detailed description.